Brothers and Sisters
by lindstheravenclaw
Summary: The loyalties in Hogwarts and the magical world are turned on their head as one young girl enters the scene. Harry Potter and Draco Malfoy share an adoptive sister through a series of coincidences. How is Harry's and Draco's upbringing different when their lives gain such a chaotic force of nature like Marabelle, the daughter of Bellatrix Lestrange? (No pairings decided yet.)
1. Chapter 1

A delighted yell echoed through the empty Manor. The sound was immediately followed by a shushing sound that sounded even louder then the yell as the sound vibrated through the manor like a slithering snake. The kitchen door leading out into the gardens squeaked shut and two shadows hurried from each carefully trimmed tree to the next, keeping in the shadows as much as possible. The full moon made it hard for the two small figures. The silver rays reflected on the hair of the slightly taller figure lighting it up in an eerily silver glow, like a halo. The smaller shadow's curly mass of black heavy hair swallowed up the light like a black hole. No reflection, no silvery halo, only darkness and shadows. The curls shook as the small child giggled. The taller child didn't shush his sister this time. They were outside and safe from the concerned looks and worried restrictions laid down by their mother.

 _She is too afraid_. The boy thought. _We are kids. We need fun. And if she doesn't let us have fun any way, we will have it our own way_. He glanced to the side at his sister seeing only the shaking curls on top of her head. He loved this little human next to him with a fervour that surprised everyone in their small family. He enjoyed having a playmate and study partner almost as clever as himself. Of course, she couldn't be better than him, she was a girl after all. He shifted the broom he was carrying from his left hand to his right to avoid a branch sticking out from the trimmed tree, poking the little girl in the process.

"Hey, watch that thing." The curls mumbled and flew in an arc around her impish face as she glared at him.

"Sheesh. Was an accident, Belle." He smiled down at her. She laughed and stuck out her tongue.

"Let's see if I can catch you today!"

"Haha, you wish Slowpants." He grinned. "This is ok, let's go, go, go." The impatience was clear to hear now. He just wanted to fly already.

After a few seconds, he was grinning at the little girl who was still on the ground tying her hair into a resemblance of a ponytail.

"Careful, brother. Don't want to be scraping you of the ground later. Would be a shame to squash this beautiful flower patch with your mangled body." She leaped into the air and took of surprisingly fast headed straight towards the boy.

"Oi!" The little boy started laughing as he took off after the offender. "Come back here."

"Hah, come catch…" The rest of the shouted response was carried away by the wind as the two shapes started looping around each other and trying to catch up with the other one. The laughter carried down to the little temple hidden behind the little stream some way further into the garden. A dark large shape tore itself away from the temple and ducked behind the big fir trees right behind the red structure.

* * *

The oblivious children started tossing a ball between them. The shadowed figure on the ground continued watching between the branches. The silver headed boy was elegant in the air, gracefully swooping up and down like a born hunter. There was no rush in his movements, only a calculated change form one position seamlessly into the next. The black-haired mess was pure chaos. She did somersaults and loops and reckless manoeuvres that made the little boy wince a few times and shout something at the little girl. She seemed elated by the attention and continued with her flying tirade. The wind carried them towards the temple and now they were right above it. The moon caught the teeth of the shadow as the creature bared his teeth in a grimace resembling a grin.

The plan was going almost too perfect.

 _Oooooh juicy. No – remember the plan. The plan! Not the girl, not the girl, not the_ …

* * *

The children grew tired and even the little black chaos slowed down somewhat. The girl threw the ball a bit too much to the side and the tired boy didn't react fast enough.

"Ugh, you go get it Belle. You threw it too sideways." The boy protested as he halted his broom midair.

"Uhm, you missed the shot though. You go get it."

"Aww come on. That's unfair and you know it.

"It's not."

"'Tis."

"Not!"

"Is."

The boy remained calm as the girl's curls bounced in frustration.

"Breathe Belle. You gotta keep that temper down." He said soothingly as he started gliding down towards the temple. "Notice where it fell?"

The little girl glided behind him, her chest rising with the overly exaggerated breaths she was taking. The method their latest tutor was teaching her worked it seemed. She would have to tell him. And thank him, she remembered like her Mama told her. You thank people for something nice that they do for you or give you. Even though he is well paid. So technically she didn't NEED to thank him. He's only doing what he's told. Ok, no thanking.

She landed in front of the red temple and leaned her broom against the stairs. She never liked this shrine-like building. One of their tutors told them stories of some Angry Gods who could be only appeased by temples and shrines and this temple was supposedly modelled after one of such temples.

 _Maybe someone will build a temple for me one day. I bet it's not that hard to get some followers and start a revolution and then get some temples and houses and gold with no work involved. Evolution through revolution._

She laughed at the phrase. A different tutor tried explaining a notion in a book to her and used it. She looked the words up in a dictionary and liked what it said. Make the world better by making it more how I want it.

 _Like the Dark Lord_. She smiled. She liked her Pa's stories about those times. Suddenly she was interrupted in her thoughts by her brother's voice from the side of the temple. She walked around and saw him standing there, broom in one hand, ball in the other, grinning wildly.

The shadow pounced. The damned girl screamed, making the little boy turn around and swing that blasted piece of wood around. The silver-haired boy was thrown away as the creature swiped a massive paw at him. It's brain got fuzzier as the girl continued on screaming.

"Run Belle!" The boy screamed wildly as he tore off in her direction. She snapped and started sprinting as fast as her short legs would allow her. The beast leaped behind them and in two big bounds caught up with the fleeing children, swiping his paw at the boy again. The boy went flying taking the little girl with him as they slammed into the stairs off the temple.

"Broom!" The girl screamed but the wolf – it was a massive wolf she now noticed when her brain seemed to wake up - the wolf was already on the stairs of the temple, tongue out, as if enjoying smell of fear in the air.

"Jump over there," the boy growled to the side "and get out of here!"

"I'm not leaving you." She resolutely backed away from the creature with him, snatching the boy's hand in process and holding on for dear life.

 _So this is how I die_. And a little voice in her head replied I'm scared. Tears started rolling down her cheeks. The boy's face was scrunched up as he positioned himself in front of the girl.

"Then we BOTH die. Get the broom and GO!" He hissed, his heart beating chaotically as his brain froze with terror.

"NO!" She screamed and the wolf jerked at the high-pitched sound pouncing on the threat as his wolf brain registered it. The impact knocked the girl down as his teeth sank into the shoulder of the little body. The boy was sent flying through the flimsy wooden rail. The girl howled incoherently.

"Arghhhhh. RUUUUU-aaaaaggggh- NNNN!" He batted a heavy paw at the little creature's face to stop that excruciating sound that pierced his brain. She squirmed in pain and he bit into the nearest limb which happened to be an arm, his paws holding down the little bundle of blood and meat and … The wolf stopped - and sniffed. It's pupils widened slightly as it stepped away and looked down at the girl properly.

The beast was flung from her with such force that he broke one of the pillars holding the temple and slammed into the trees behind it.

The girl continued howling in pain as somebody started muttering spells and waving their wand all over her body. Her eyes focused one last time on the silver halo illuminated by the moon from one side and forced out: "Da..".

The world turned black and cold.


	2. Chapter 2

**Disclaimer: If I were JKR I would definitely not be teaching English as an income, while trying to figure out the way to take over the world.**

 **Author's note: English is not my native language, so please excuse any blunders. Also I don't have the story actually thought through or prepared, so some inconsistencies are likely to happen. I will write this as it comes into my head. Got some thoughts and going to try and prepare the plot outline or something.. Have fun!**

* * *

Severus Snape woke with a sudden feeling that something was wrong. His wand appeared in his hand as he subconsciously summoned it from its holster tied to his forearm even in his sleep. He didn't survive this long just by luck after all. He immediately noticed that his fireplace has received a floo call and Narcissa Malfoy's head was poking through the green flames. Snape scanned the rest of the room but didn't feel any other presences, concluding it's not a trap to grab his attention.

"Sev. We need help. There's been an … accident." Even though the fire distorted Narcissa's elegant features, he could tell she was anxious.

"Draco? Is he…?" Fear gripped Severus as he imagined the only person that actually seemed to partially like him injured or worse dead.

"No, no, no. It's .. a friend. A very .. uhm.. dear friend. She's been… bitten." Narcissa gulped as wrath coloured Snape's features. She knew of his dislike of the species because of the incident years before during his school years. Her husband was probably one of the only ones to know the full truth. And of course he had to share it with his wife.. after some persuasion.

"Well, she's doomed. There's nothing that can be done. It is the full moon so she will turn. I can't save her sorry. Take her to Mungo's to ascertain the extent of the damages and it's life is even worth living." He didn't look too sorry. He obviously didn't wish this on anyone but if anyone's stupid enough to be out during the full moon, serves them right.

"Severus. She wasn't just bitten. He must have been angry. Her face... We can't take her to St Mungo's. Come and Lucius will explain. Please Severus." Narcissa pleading with him was a new experience. Snape's curiosity about this "female" friend awakened, he turned and in two strides crossed the small living room to his cabinet where he stored his rarer potions. He picked a few bottles, slung an emergency crossbody kit over his shoulder and disappeared into the fireplace clearly pronouncing "Malfoy Manor".

* * *

The big front hall where he appeared let in moonlight through the tall windows on both sides creating a tangle of shadows on the marble floor. Narcissa waited fidgeting by the doors leading to the West wing which had all the Malfoy's rooms. Snape frowned at Narcissa behaviour. This elegant woman rarely let any emotion show. They strode in silence until they stopped in front of Draco's room. Snape raised an eyebrow and turned to Narcissa.

"You said…"

"Yes, Draco is fine. I need you to give me an unbreakable vow first. You will not tell anyone of this person nor will you discuss her or the circumstances that have led to you being called here with anyone other than me, Lucius and Draco." She was watching his face intently. This moment decided everything. Severus's eyes narrowed. This did not bode well. Where they hiding somebody from the war? No, Lucius wasn't stupid. He knew the risks.

Severus frowned again. He didn't like this one bit. He thought of Lucius as one of his only something like a friend. How truly dangerous could this be for him? If Dumbledore wanted to know, he could say it was necessary for the other side to trust him. And he was a bit more than curious about this bitten person. Sighing he repeated the oath to her and his magic flickered around him in an orange aura as it accepted the bond.

Narcissa turned around and opened the door opposite Draco's. Snape raised his eyebrows. That room was never used. He never saw anyone enter or leave when he was visiting Draco or Lucius. He stepped into the large bedroom and quickly took in his surroundings while striding towards the blonde-haired man who sat slumped in a chair by the big four poster bed.

"Lucius, he's here." Narcissa was a step ahead and laid a hand on her husband's shoulder as Lucius turned around to look at Snape, who took in a sharp breath as he saw the look in Lucius's eyes. He had seen him like this once when Draco fell off Lucius' broom (which he snuck out of the broom shed) when he was 3 years old.

As Lucius straightened, Snape finally saw the little form in the bed, once again taking in a sharp breath. The little girl couldn't be more than 5. One half of her face had deep gashes in them as the beast tore through the little dainty face. Her dark curly hair had him frown deeply again. WHO was this little girl that had the Malfoy's so worried over her. That didn't just happen. He stored the information into his sort through later mental pile and set to work calling Dobby, Draco's house elf. No questions asked. He knew they would tell him later what he needed to know. As Potion's Master it was his duty to help the little unfortunate bundle. She was spelled asleep.

The painkillers the wizard world had on offer probably didn't work much here. The pain was too much for the little girl. Severus drew a blood sample and muttered a spell over the little flask.

"The blood has already bonded with hers. I can't stop the transformation." The glance at Lucius told him he really cared for this little girl. "But I can try something else. Something I have never had the opportunity to try.." He squinted his eyes shut.. If this worked.. He would be hailed as the saviour of the future werewolf world. Excitement began pooling in his stomach.. He didn't have much time.

"Lucius.. I might be able to do something…" The silver-haired man looked at him with such a hopeful look in his silver eyes that Severus was taken aback.

"Severus. I … That girl is as dear to me as Draco is. She is everything I ever hoped for in a child. If you can do anything to save her, help her from her… fate, then I will give you anything. What's on your mind?"

* * *

Draco was spying through the keyhole of his room. He cast a basic charm to check if the coast was clear. He couldn't wait to get his own wand. His granpda's was cool, but it didn't feel right. His little sister gobbled up all the books she could reach once their Mother taught her to read two years back. The one to detect a presence was one they often used on their expeditions into the kitchen late at night.

He tiptoed out of the room and pressed his eye to the keyhole of the room opposite.

* * *

"I won't have her threaten Draco, Lucius!" Narcissa was pacing back and forth in front of the bed.

"Ciss, if we don't do this, she will turn every full moon into a rampaging beast. With this treatment we at least have a chance she will have a normal life! It could even counteract the poison in her blood! I will not let you send her away, without trying to keep her a full part of this family!" Lucius was holding onto one of the pillars of the bed, positively glowering at his wife. "She is family! Your family I might add! We go forth with Severus's idea. It can't make it any worse right?" He snapped back at the potion's master who was busy cutting some plant.

"I don't think so. The ingredients are prepared and conserved to be used immediately. The health risks aren't greater than what is already happening to her. I think this is the only way to proceed, if we are to try to save her. Her age might be a concern as I never thought I'd try this experiment on a young child. But on the other hand her age might prove a bonus in easing the transformation." The uncharacteristically long speech for the professor didn't alleviate Narcissa's concern.

"Try what you want. I am not keeping that animal in my house any longer… I agreed Lucius while she was normal, but no one is threatening my ONLY child! She was wild at the best of times, and who knows what will happen with her now!" Narcissa turned on her heel and strode out so fast, she managed to notice the door of her cherished son close. She opened it quietly and noticed Draco's form evenly breathing underneath te quilt covering him. Sneaky cunning Slytherin. That was unfortunate but she would deal with that in the morning.

* * *

"We have to wake her up for this." Lucius moved to the other side of the bed and waved his wand over the little girl. "And silence the room, it is going to hurt her and I doubt she will be quiet." Severus continued and Lucius swung his wand in several motions.

"Marabelle, I am here." Her father knelt next to the bed as she wimpered.

"Daddy. It hurts." She went to touch her face as her dad's hand gently caught her arm.

"Don't my love. It's going to go away hopefully. This nice man" Severus sneered at the term but controlled his face as the girl's dark eyes turned to face him "is going to help you."

"Hi, I'm Mara." The little girl stuck out her bandaged arm and tried to keep the wince out of her voice.

"Severus. Pleased to meet you Mara." Oh, he was going to skin Lucius later. Her eyes, voice, hair, posture.. Sat in front of him was definitely the daughter of Bellatrix Lestrange.

"I'm going to give you some potions. Now, the first one is going to hurt. The second is going to make you see things and the third is going to calm you and put you to sleep." Severus tried to keep a neutral tone in his voice when speaking to the embodiment of the craziest woman he ever knew.

"Okey. Can I call you Sev? Severus is a bit of a mouthful." The little girl surprised him into agreeing without thinking. Lucius snickered and Severus could swear he heard a muttered "Sev, my arse."

"Ok, you may call me Sev. Now drink up Mara." Her little hand took the uncorked blood-red potion from his palm and after a brief look and subsequent nod from her father, she drank it.

Lucius was expecting many things, but not the heart-wrenching screams of a small 5 year old, that he loved like his own child. He glared at Severus, who looked evenly back.

"Wait, my friend." And they waited. Severus with an old muggle watch counted the seconds. The girl quieted in a few minutes and started falling out of consciousness.

"Keep her awake! She must be awake or we lose her!" Severus snapped at Lucius who immediately started muttering waking charms. The girl jerked awake.

"Here, bite this." Her father conjured a piece of fabric and stuck it into his daughter's mouth.

This was pure torture. The little girl wreathed on the bed, sweated profusely and you could see the panic and fear in her eyes. He took hold of her hand and started stroking it and muttering calming words, keeping an eye out for any signs of passing out again.

Severus took hold of the second potion and glanced down at his watch. "Now." Lucius grabbed the piece of fabric and held open the little girl's mouth, while tear streamed down his face. He felt ashamed that Severus saw him like this, but he couldn't care anymore. His little Mara was suffering something much worse than a Crucio by the looks of it. How he wished he could take the pain away... And suddenly the pain seemed to disappear as the girl stilled. Her eyes turned light blue and focused on the ceiling.

"Sev… Severus… Is she.. Is she in there now?" Lucius still held the little girl's hand stroking it and not even looking up.

"Yes, she is not in possession of her own body, so she doesn't feel any pain. As she descends, the pain will start again, and then you have to hold her still as I spell this inside of her." He showed Lucius the golden glowing ampule with the few drops inside of it.

"Don't even get me started on how much you owe me for using this." He muttered and settled to watch for the return of the little girl's spirit.

* * *

A tired Severus and a distraught Lucius walked into the latter's library, basically toppled over into the big armchairs in front of the fire and both summoned the whisky from the hidden place in Lucius's working table at the same time.

"I shouldn't be too surprised you know this beauty's hiding place." Lucius clinked his glass into Severus's and gulped down half the glass.

"Tell me Lucius. Who is she?" Severus swirled the liquid in his glass and didn't lift his gaze from the golden liquid, so similar to the third potion.

Lucius stood and walked over to the big window behind his desk. The gardens spread out in front of him and he cursed himself for not looking out earlier while the children were outside. He might have prevented the attack. He also thanked the universe for making him look out at the moment he did look out. Draco might have been hurt more severely. Lucius managed to heal the two swipes of the paw, the beast managed to do to the boy. He would be scarred for life, but he wasn't bit. A bite turns a person into a werewolf. A scratch disfigures for life but doesn't contain the power to transform. Draco would always have 4 scrapes across his chest and arm, but not turn. Thank God for that. He didn't want to think about what Narcissa would do. Snape ehm-ed and turned Lucius's attention back to the real world.

"She's Bellatrix's daughter. Bella gave birth a few months before the attack on Harry Potter. I do not know who the father is. Bella didn't say."

And therein lies Lucius's problem, Severus deduced. If she was, hell forbid, Voldemort's daughter, the world would demand she be executed. Rabastan and Rudolphus were another possibility. Some other follower of the Dark Lord was possible as well.

"You see, Severus, don't you? Whoever the father is, her life will forever be in danger because of it. The world might want her dead because of who are her parents. They might want to use her. For good or for evil. I won't let that happen. I took her in. She's my niece after all. I .. I persuaded Narcissa that she would be an asset to this family. To motivate Draco, to influence people, to arrange a marriage for her that would benefit us. I.. wanted to use her…" Lucius stared out over the gardens as dawn's colours creeped over the temples and hedges.

"But you grew to like her." Severus growled. His nerves on edge.

"I grew to love her. As the daughter we never had. Narcissa has always wanted a daughter. We were never blessed. Draco loves her as a sister. A true sister. But Narcissa, she never got over the fact the child is not hers. There is no mothering instinct in her towards Marabelle. I fear she will be against Mara staying here after all this. I .. can't argue with her. I love Marabelle, but … I won't be able to protect her here anymore. Draco will be heartbroken. I will be heartbroken."

Severus had no idea what to say. The situation was impossibly complex. No one could find out the child's true name. No one could find out what he did for her. If they did they would wonder why the girl got such a treatment from him. His genius would have to wait. Especially since they weren't aware what had happened with the girl's blood yet. As he thought of the little face, he felt a spark in his heart. The little bundle was brave. And the way she immediately claimed him as her own, "Sev" echoing in his heart. Only one other person had ever called him this.

He stamped on the thought violently. Not happening here. No. Family. Wait. Andromeda!

"What about Andromeda? She would take the girl in." Severus's brain was in overdrive again.

"Andromeda? But .. yes. That could work. Go to sleep Severus and return when you have calculated Mara will wake. I will try and prepare the family for what is to inevitably come."

Lucius bravely walked out of the study, leaving Severus alone. The loos of a daughter. The loss of a sister. But Narcissa would make the girl's life living hell here. He curbed her until now. But he couldn't guarantee the girl's safety anymore.


End file.
